An exiled Uighur group says Chinese authorities have turned the northwestern region of Xinjiang into a "police state," three years after the outbreak of deadly riots between ethnic Uighurs and settlers of China's Han majority.

A Washington-based spokesman for the World Uyghur Congress, Alim Seytoff, Thursday said Xinjiang security forces have intensified street patrols of Uighur neighborhoods in recent days, making residents feel like they are living in a "war zone." He made the comments on the third anniversary of the start of the riots that the Chinese government said killed about 200 people, both Uighurs and Han Chinese.

Xinjiang Communist Party Chief Zhang Chunxian met with security forces in the regional capital Urumqi on Wednesday, urging them to use "iron fists" in crushing separatists, extremists and terrorists. Xinjiang is home to millions of Turkic-speaking and largely Muslim Uighurs who accuse Beijing of persecution and turning them into a minority in their homeland by flooding it with Han Chinese settlers.

Seytoff said Zhang has escalated the repression of Uighurs since succeeding Wang Lequan as Xinjiang's top official in 2010.

"Initially he came, he presented a smiling happy face to the Uighurs, trying to appease the Uighurs in a way and even create some preconditions for peaceful coexistence between indigenous Uighurs and Chinese settlers. But soon, he showed his true colors. He's actually not any different than Wang Lequan, if not worse and more skillful," Seytoff said.

Zhang has said it is Chinese government policy to protect the legitimate practice of religion. But he also has vowed to crack down on Uighur extremists whom authorities accuse of using Islam to incite violence.

The Chinese government has increased aid and investment in Xinjiang since 2009 to deal with what it considers to be the root cause of unrest: poverty. Seytoff said poverty plays a role in Uighur grievances, but accused Beijing of having a different motive for sending funds to the region, also called East Turkestan by some Uighurs.

"The development is really for the benefit of the Chinese immigrants who come to East Turkestan - their jobs, health care and everything is guaranteed for them, while the same thing is denied to the Uighur people. Yes, the Chinese government poured millions of dollars in the area ... but they did all of this to speed up the immigration of Han Chinese. That's the whole idea of their development push," Seytoff said.

A prominent Han Chinese activist in Xinjiang, Hu Jun, said Beijing's policies have created ethnic tension where it did not exist before.

“My personal view is this: the ethnic groups in Xinjiang don't have problems to begin with, and many times it was the government that tries to emphasize the hostilities among the ethnic groups," said Hu. "On some issues, it was the government that purposely tried to overstate the ethnic hostilities. Through my years in dealing with Uighurs, Hazak, Kerkas and Hui, China’s Muslims, ethnic groups are easygoing people. They don’t have big conflicts with the Han. They are commoners as we Han people are.”

In a report released Thursday, rights group Amnesty International said Xinjiang authorities continue to silence Uighurs who speak out about alleged human rights abuses from the riots that began on July 5, 2009.

Amnesty said "dozens, if not hundreds" of Uighurs remain in detention after disappearing during the unrest, which erupted in Urumqi and went on for weeks, triggering a major security crackdown and arrests.

Amnesty China researcher Sarah Schafer said many family members of the missing have suffered harassment from authorities when trying to obtain information about their loved ones.

"We're demanding that the government comes clean on these cases of disappearances because this is absolutely unacceptable. It is incredibly difficult to get info from Xinjiang. These families are starting to speak out but at great risk to themselves," Schafer said.

Schafer said Patigul Eli, the mother of a missing Uighur man, reported meeting at least 30 other families who also have tried to get information from Urumqi authorities about relatives who had disappeared.

"For three years she hasn't known where her son is or even whether he is alive or dead, and she's begging for answers from the government. Unfortunately no answers have come," Schafer said.

The Amnesty researcher said some detained Uighurs have been denied a free trial because Xinjiang authorities consider them to be terrorists.